Hammond L series User Manual

4-17.
ORGAN
DOES
NOT
PLAY.
-
a.
If the
generator
motor
is
not
turning
and
the
tubes
do
not
Ught
when
the
switch
is
I
in the
"on"
position,
cheek
the
power
I
wiring,
power
switch,
line cord,
line
cord
plug,
and
wall
outlet.
b.
If
the
generator
turns
and
the
tubes
light,
^-
but
no
sound
can be
obtained
with
all
controls
in
playing
position,
the
most
likely
source
of
trouble
is
the
ampUfier.
In
most
respects
this is a
conventional
I
amplifier
circuit,
and
the
schematic
dia-
grams,
Figures
5-1
through
5-4,
will
enable
the
service
man
to
locate
the
trouble.
4-18. KEY DOES
NOT
PLAY OR
HARMONIC
IS
MISSING.
-
This may
mean a
dirty
key
contact, a
broken
connection,
or
a
dead
note
in
the
generator.
The
steps below
will serve to
isolate the
trouble.
NOTE
Checks a
through
i,
following,
must be
performed
with
the
'
DRAWBARS tab
depressed.
a.
Ordinarily
only
one
of the
several
frequen-
cies
used
on the
key
will be
missing.
This
can
be
determined
by
holding
the
key
and
operating
each
drawbar
for that
manual,
observing
on which
drawbar
the
key
fails
to play.
Reference to
the
manual
wiring
chart.
Figure
1-7, will
tell
which
fre-
quency number
is
missing.
b.
See whether the
same
frequency
is miss-
ing
where
it is
used
on
other
keys
of the
same
manual.
The
wiring
chart
will
tell
with
what
other key
and
what
other
drawbar
you
should
get
the same
fre-
quency.
If
it
is
missing
on one key
but
not
on
others,
a
key
contact
is
probably
dirty.
In
some
cases it may
be
cleared
by
striking
the key
1 5
or
20
times
in a
^
rapid
staccato
manner to
loosen
the
dirt.
If this
procedure
is
not
effective,
adjust-
ment
of
the
busbar
shifter
for
that
manual
will
clear
it.
(See
paragraph
1-5.)
This
will
slide
the
busbars
endwise
so
they
r
present a
clean
contact
surface.
In extreme
cases,
it may
be
necessary to
hold
down
.
the
faulty
key while
making the
adjustment.
c.
If
the
frequency is
missing
on
all keys
of
1
one
manual
but
not
on the
other
manual,
I
look
for
a
break
in
the cable
connecting
one
manual to
the
other.
d.
If the
frequency
is
missing
on both
manuals, check the
manual-to-generator
cable
or the generator
itself.
e.
The
output
of any
single
frequency
on
the
tone
generator
may
be
checked by
pulling out any
drawbar
and
connecting
a
clip lead
from the back end
of the
drawbar
to the
generator
terminal
in
question. See
figure 6
for
location
of
all generator
terminals.
If
the
generator
is all right, the
note
will play
loudly.
CAUTION
Never
test
the tone
generator
with an
outside
source
of current
such
as a
continuity
meter,
as
serious
damage
may result to
the
sensitive
filter
transformers
and
permanent
magnets. By
the
above
method,
all
necessary
tests
of the
tone
generator
may be
made
with
the
current supplied
by
the
generator
itself.
f.
If it
fails
to
play,
try
touching
the
clip to
the
input
side
of the
filter coil
(not
the
grounded
tap)
and the
input side
of the
filter
condenser
(Figure
1—6)
in order
to
check
these
parts.
Disconnect
the
con-
denser
to
eliminate
the
possibility
of a
grounded
transformer.
If
the
signal
is
still
missing
at
the
magnet
coil
terminal,
it
means
that
the
tone wheel
is
not
turning,
the
coil
is
defective,
or
the
magnet
is
not
properly
adjusted.
g.
If the tone
wheel
is
not
turning,
the
frequency
of the
other
wheel
on
the
same
shaft
will also
be
missing
(with
the
exception
of
a few
wheels
which
are
alone).
On
the
generator
magnet
location drawing
(Figure
1-5),
the
two
frequencies
whose
numbers
are
connected
by
a
dotted
line
are
on
the same
shaft.
Another way
to
check
the
wheel
is to
remove
the
dampening
pad
under
the
generator
(it
is held by
the two
long
channels
which
form the
generator
frame)
and
feel the wheel
with
your
finger to
see
if it
is
turning. Each
wheel
is
located
di-
rectly
behind
its
magnet,
shown
in
Figure
1-5.
h.
If the
magnet
coil
is
defective,
the
generator
must
be
returned
to
the
factory,
as
replacement
of a
coil
necessi-
tates
dismantling
the
entire
generator.
i.
It is
possible,
although
unhkely,
that
the
magnet may
have
become
loose
and
moved
so
far
from
the
wheel as
to
make
the
note
inaudible.
It may
be
adjusted
as
described
in the
following
paragraph.

Hammond L series Specifications

General

Brand	Hammond
Model	L series
Category	Musical Instrument
Language	English